1. Technical Field
This invention relates generally to pistons for internal combustion engines, and methods of manufacturing the pistons.
2. Related Art
Steel pistons of various designs are used in a diesel combustion system which sharply releases energy from a pre-mixture of fuel-air at the end of an ignition delay period (ID). An impulsive noise signature follows which is objectionable to human hearing and is manifested as a characteristic diesel “knock.” In step with this initial energy release, a period, typically milliseconds, of a high in-cylinder temperature occurs, such as 2000-3000° C. The high in-cylinder temperature produces high NOx levels, which engine manufacturers prefer to avoid.